1907.] 



Problems in Potato Growing. 



7r 



notably liable to produce scabby potatoes, comprising shoddy, 

 peat moss litter, sawdust, and rape meal, each alone and with salt. 

 The only successes were with 53 cwts. of sawdust per acre sown 

 over the sets at planting time with and without 5 cwts. of salt, 

 and with a ton of wet peat moss and salt. The sawdust alone 

 checked the disease, and the addition of salt rendered the pota- 

 toes practically free from scab, although those on untreated por- 

 tions of the field were badly affected. The wet peat moss and 

 salt proved equally successful, yet abundant experience shows 

 that drought alone will not develop scab, and in all probability 

 it is some deficiency in the constituents of a light and gritty soil 

 which causes it to foster the development of the disease. 

 Further investigations into the cause of this disfiguring malady 

 would seem desirable. Some information respecting it is given 

 in the Boards' Leaflet, No. 137. 



Manuring. — Turning to unsettled problems of manuring, atten- 

 tion may first be directed to some striking results from different 

 methods of preparing and applying farmyard manure, shown in 

 a report by Mr. R. A. Berry, Lecturer on Chemistry at the West 

 of Scotland Agricultural College on experiments carried out at 

 Kilmarnock by Professor Wright, Principal of the College. It 

 has been the fashion of late to recommend the application of this 

 manure to a field intended for potatoes in the autumn, spreading 

 it all over the land, and ploughing it in at once. At Kilmarnock 

 this plan was tried in comparison with the method of leaving 

 the in. mure spread on the land three months before ploughing 

 it in, and with that of applying it in the potato drills just before 

 planting in the spring. The experiments were on a rotation of 

 crops of which the potato crop was the first, and the total yields 

 per acre of large plots (one-fortieth of an acre each) unmanured 

 and dressed with j< > tons of fresh farm manure applied variously, 

 as a hi »vc described, were as follows : — No manure, 8 tons 18 cwts. ; 

 manure spread in the autumn and ploughed in at once. 11 tons 

 iS cwts. 1 (jr. ; manure spread in the autumn and not ploughed 

 in for three months, 10 tons 17 cwts. 3 qrs. ; manure applied in 

 drills in the spring. 14 tons. ; cwts. 1 (jr. The givat superiority 

 of the last plan of applicati< >n is. no doubt . attributable partly to 

 loss of nitrogen incurred bv the manure on the other plots 

 in the autumn, and partly to the concentration of the manure 

 in the drills under the seed potatoes as a source of food for the 



